WEST TEXAS — As oil and gas production has surged in Far West Texas, so have earthquakes, according to a new study.
The study, published last month in the Journal of Geophysical Research: Solid Earth, used seismological data to track the number of earthquakes in a cluster near Pecos. That number has risen considerably in recent years, the researchers found, from 19 earthquakes in 2009 (the first sign of “anomalous activity”) to more than 1,600 in 2017.
The researchers, including from the University of Texas at Austin and Southern Methodist University in Dallas, note in their abstract that a lack of long-term seismological data makes it tricky to pin the earthquakes to any one factor. But the rise has occurred alongside an increase in oil and gas production, “suggesting a causal link.”
Fracking and drilling activities in the Permian Basin has more than doubled over the last decade, from around 500 million barrels of produced oil a year in 2010 to over 1 billion today. The researchers point to not only production but also wastewater injection (when oil companies inject fracked wastewater deep underground) as possible culprits.
Heather DeShon, a seismologist at Southern Methodist University, is a co-author on the paper. In an interview with The Big Bend Sentinel, she credited the appearance of earthquakes in the Dallas/Fort Worth area for her interest in the subject.
As fracking and oil and gas production picked up around Dallas, the area started experiencing earthquakes in 2008. That was intriguing, DeShon says, because the ancient faults underneath Dallas had not caused earthquakes in 300 million years.
DeShon and other earthquake experts theorized that drilling and injection were disturbing the faults, reactivating them with waves of pressure and water, and releasing what DeShon describes as “ancient leftover energy.” Further research seemed to confirm that hypothesis.
Those findings helped spur the creation of the Texas Seismological Network in 2016, which measures earthquakes in the state. Operated by the Bureau of Economic Geology, researchers like DeShon relied on its data, as well as seismic readers in Lajitas, for their West Texas study.
Despite the ominous sound of “ancient leftover energy,” DeShon said the earthquakes around Dallas aren’t necessarily there to stay. Further research suggests that the fault lines would accommodate the pressure and stop quaking — so long as people stopped fracking and injecting wastewater underground.
“That’s not a bad finding,” she said. “That’s actually fairly good news for the Dallas/Fort Worth area.”
The situation in West Texas is more complicated. Mountainous and located near the Rio Grande rift, the area has naturally occurring quakes — including the 1995 Marathon earthquake and the 1931 Valentine earthquake, the latter of which caused widespread damage. It’s still the most intense earthquake recorded in the Lone Star State.
That reality makes it harder, DeShon says, for researchers to separate naturally occurring earthquakes from industry-induced ones. It also raises the stakes. While many of the recent earthquakes in relatively flat North Texas have caused minor tremors, earth scientists aren’t yet sure how bad the quakes in West Texas could get.